Manukau Mayor Len Brown has vowed to unite Auckland as he begins a long duel with Auckland City Mayor John Banks to be the first Auckland Super City mayor.

Speaking to 250 supporters at Cornwall Park - a legacy from the "father of Auckland" Sir John Logan Campbell - Mr Brown, who is 52, said Auckland needed a mayor "who brings people together, who is not a divider".

The message was a dig at Mr Banks' combative reputation. It was also the basis of building a coalition of like-minded community groups to contest next year's elections.

"I want to say when I get into a campaign I get in to win," Mr Brown said.

Last night, Mr Banks acknowledged Mr Brown would be a strong centre-left candidate against his centre-right prescription for the Super City.

"I can't make any judgment about his musings or machinations, except to say I have been elected to office 11 times and I would like to think I have my strengths. I certainly have some weaknesses, but I believe I can do a really good job," Mr Banks said.

So far, Mr Banks, 63, and Mr Brown are the only declared contenders for the mayoral position, which comes with executive powers to choose a deputy, chairs of committees and propose a $3 billion budget.

Mr Banks has been working behind the scenes to ensure he is the only serious contender on the centre-right. Likewise, Mr Brown on the centre-left.

Auckland Regional Council chairman Mike Lee is contemplating standing for the mayoralty, but faces a lack of support from the centre-left and a UMR Research poll last month showing Mr Brown marginally ahead of Mr Banks.

Waitakere Mayor Bob Harvey is not expected to stand, but may seek a seat on the Auckland Council and deliver the eco-vote to Mr Brown.

"I hope Len will be the only mayoral candidate from the left. Len is young, he is bright, he has got a heart of gold and he will unite Auckland, not divide it," said senior Labour MP David Cunliffe.

Mr Brown, who is standing as an independent, said Auckland faced a huge challenge, but also many opportunities.

"I believe that our people, our communities must be at the centre of the new Auckland. Communities have been central to all that I have worked for. Local government must be local. Especially now. Especially as Auckland comes together."

Among his policies are:

A fully integrated transport system, including a CBD rail tunnel, a rail link to the airport and doubling of public transport use in 15 years.

Public ownership of port and airport shares and water assets.

High speed broadband within five years.

Keep rates rises down.

Support for Maori seats on the Auckland Council.

Extending Manukau's free entry to swimming pools across the city. Re-establishing the Auckland Flower Show.

Rotating council meetings around the region.

Mr Brown, who suffered a near-fatal heart attack in May last year, said he had had an amazing recovery, his blood pressure and cholesterol levels were good and he was walking for between 45 minutes and one hour each day.

"If I had a sense of doubt that there was something not right about me still then no way for a second would I contemplate this."